From 4e89d629dc72965ea05a9b5231862ffd9c9dab55 Mon Sep 17 00:00:00 2001
From: John Olender <john.olender@gmail.com>
Date: Fri, 5 Sep 2025 06:11:28 -0400
Subject: [PATCH 5098/5403] drm/amdgpu: Fix NULL ptr deref in
 amdgpu_device_cache_switch_state()

Kaveri has no upstream bridge, therefore parent is NULL.

$ lspci -PP
...
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Kaveri [Radeon R7 Graphics] (rev d4)

For comparison, Raphael:

$ lspci -PP
...
00:08.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Raphael/Granite Ridge Internal GPP Bridge to Bus [C:A]
...
00:08.1/0e:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Raphael (rev c5)

Fixes: 1dd2fa0e00f1 ("drm/amdgpu: Save and restore switch state")
Link: https://lore.kernel.org/amd-gfx/38fe6513-f8a9-4669-8e86-89c54c465611@gmail.com/
Reviewed-by: Candice Li <candice.li@amd.com>
Reviewed-by: Yang Wang <kevinyang.wang@amd.com>
Signed-off-by: John Olender <john.olender@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index bdfb80377e6a..b20383021b50 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -7161,7 +7161,7 @@ static void amdgpu_device_cache_switch_state(struct amdgpu_device *adev)
 	struct pci_dev *parent = pci_upstream_bridge(adev->pdev);
 	int r;
 
-	if (parent->vendor != PCI_VENDOR_ID_ATI)
+	if (!parent || parent->vendor != PCI_VENDOR_ID_ATI)
 		return;
 
 	/* If already saved, return */
-- 
2.54.0

